1. Field of the Invention
The present invention relates to a method for wiring design for a variety of wiring boards such as a wiring board of semiconductor device packages and a printed circuit board (PCB) of electric apparatuses.
2. Background Art
A variety of wiring boards each of which has a plurality of wiring surfaces are available such as a semiconductor package wiring board and a PCB for various electric apparatuses.
For these wiring boards, the wiring design is desired to be of a high integration and a high accuracy. This desire may be accompanied by a tendency of taking a longer time to design the wiring.
Accordingly, to shorten the design time, in the past, a method was employed for automatically designing the wiring by using an automatic wiring design apparatus. This shortens the wiring design time than the method of a designer designing the entire wiring manually. However, as described later, such an automatic wiring method by use of the automatic wiring design apparatus may give rise to a design error referred to as a design rule error in some cases. In such a case, it is difficult to work out a design in such a manner as to eliminate design rule errors by using the automatic wiring design apparatus. Thus, the designer worked out a design to eliminate design rule errors manually. However, wiring, if it is of a high integration, has taken a prolonged time for manual design by the designer, thus resulting in a long time to design completely.
A method for automatically eliminating the design rule errors is disclosed in Japanese Patent Laid-Open No. 2007-287023.